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US 7,443,515 B2Granted
Apparatus for measuring optical properties of tested optical system using interference
AssigneeCanon Kabushiki Kaisha
InventorSeima Kato
Life of this patent
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Abstract
A measuring apparatus for measuring the optical properties of an optical system including a mask with a slit and a window, upon which different light beams are focused to derive an interference pattern. The interference pattern can be used to obtain optical properties of the optical system.
Claims7
An apparatus for measuring the optical properties of an optical system using interference comprising:
- a first mask comprising a pinhole and illuminated with light from a light source to produce a spherical wave from the pinhole;
- a light-splitting device for splitting light from said first mask into a first light beam and a second light beam;
- a second mask provided with a first slit, upon which the first light beam is focused, and a window, upon which the second light beam is focused;
- and
- a detector for detecting interference fringes formed by the interference of a portion of the first light beam passing through the first slit and a portion of the second light beam passing through the window.
2 more elements
An exposure apparatus comprising:
- a projection optical system for projecting an image pattern of a reticle to a substrate;
- and
- a measuring apparatus for measuring, using interference, the optical properties of said projection optical system, wherein said measuring apparatus includes
- a first mask comprising a pinhole and illuminated with light from a light source to produce a spherical wave from the pinhole,
- a light-splitting device for splitting light from the first mask into a first light beam and a second light beam,
- a second mask provided with a first slit, upon which the first light beam is focused, and a window, upon which the second light beam is focused, and
- a detector for detecting interference fringes formed by the interference of a portion of the first light beam passing through the first slit and a portion of the second light beam passing through the window.
4 more elements
A device manufacturing method comprising the steps of:
- exposing a photosensitive layer on a substrate using an exposure apparatus;
- and
- developing the exposed photosensitive layer, wherein the exposure apparatus includes
- i) a projection optical system for projecting an image pattern of a reticle to the photosensitive layer, and
- ii) a measuring apparatus for measuring, using interference, the optical properties of the projection optical system, wherein the measuring apparatus has
- a) a first mask comprising a inhole and illuminated with light from a light source to produce a spherical wave from the pinhole,
- b) light-splitting device for splitting light from the first mask into a first light beam and a second light beam,
- c) a second mask provided with a slit, upon which the first light beam is focused, and a window, upon which the second light beam is focused, and
- d) a detector for detecting interference fringes formed by the interference of a portion of the first light beam passing through the slit and a portion of the second light beam passing through the window.
6 more elements
Dependencies are inferred from the claim text.